User ID power-up adds a stape generated user ID (X-Stape-User-Id) to Request Header for each Incoming Request inside the server Google Tag Manager.

User ID consists of a hash of:

• user IP
• User-agent
• TLS settings
• Hostname 

To use User ID  power up, log in to your stape.io account, open the sGTM container go to the Power Ups tab, and click Use User ID power up. After that, enable the power-up and click Save. 

To check if the User ID power-up works correctly, open sGTM debugger, click on the Requests tab, and open the incoming request. You should see X-Stape-User-Id in the Request Headers section. 

To use these Requests Headers in the server Google Tag Manager create a new variable with the variable type Request Header and type Header Name.